The Ford Barn

fjz · 07-23-2018, 07:05 PM

After having my gens and vr's tested only to learn my original gen and rebuilt gen were both OK and my original vr is toast but the new one is OK I have come to the conclusion my amp meter is toast. Put my volt meter on the vr battery terminal and it read 6.94 with the engine on a fast idle. Been looking for an amp guage and the ones available do not have 2 terminals but rather a loop which I suspect the wire passes through. Has anyone switched backs on an amp guage?

JSeery · 07-23-2018, 07:53 PM

The loop style is much "safer" because of the design. It is possible for the two terminal amp meters to malfunction resulting in a lot of heat and possible fire. Remember all of the amperage coming from the battery to the vehicle circuits passes through the ammeter on the terminal style. With the loop style the current is just passing by the meter (through the loop).

koates · 07-24-2018, 12:52 AM

So why do you think your ammeter is toast ?? Are the terminals burnt ? Also no good checking the generator voltage at a fast idle. You need the engine revs at 2000 RPM plus for around 3 minutes to test the generator output and voltage regulator setting which should be 7.3 to 7.5 volts. Do yourself a favour and get rid of that 10 year old battery and buy a new optima 6 volt battery. An old flat or faulty battery can effect the voltage reading at the regulator.

fjz · 07-24-2018, 11:59 AM

Had my rebuilt generator and new voltage regulator tested and both are good. Did a voltage test and reading 6.94 at a fast idle. Amp gage reads -2. Suspect gage is bad. The replacement gages listed show a loop at the back whereas my original has 2 terminals. Has anyone been able to change the backs or should I connect my 2 wires run it through the loop? I also think my heat gage is bad as it reads hot when off. How do I check this gage?

fjz · 07-24-2018, 12:13 PM

Koates my battery is also new. Reads 6.3 before I start. Reading 6.9 running tells me the gage is bad as it should not read -2 amps. Thanks Seery. Will order a new gage and connect my wires. How do I check the heat gage?

JSeery · 07-24-2018, 01:33 PM

Sponsored Links (Register now to hide all advertisements)

There have been a number of past threads on checking gauges. Basically use a 1 1/2 volt battery to see what the gauge reads, should be around mid gauge. On the -2 amps, have you tried switching the wires on the terminals?

fjz · 07-24-2018, 02:15 PM

No but I will.

solidaxle · 07-24-2018, 05:40 PM

Quote:

Originally Posted by JSeery

Two recent Koats post:

A quick easy test on the generator only. Join the Gen and Field wires together at the regulator but have them disconnected from the regulator. Connect an analogue DC voltmeter to the two connected wires (NEG voltmeter wire) and the POSITIVE voltmeter wire to ground. This is assuming your Ford is original POS ground. The scale on your meter needs to be 20 to 30 volts DC. Start engine and rev it up to 2000 RPM or so and the voltmeter reading should rise quickly to the end of the scale as the revs rise. IF volts are zero or low as in 6 volts or so then the generator is faulty. Its a bit hard using a digital multimeter set to DC volts to read this. An old analogue type voltmeter is best. Just do that test ONLY and report results. Regards, Kevi

Get your car hot and up to the point where it is not charging again, leave it running and disconnect the field wire, (middle one ) from the voltage regulator and move/connect it over to the Armature or Gen terminal. Rev engine up and read voltage at generator terminal of regulator which should go to 8 volts plus. This is providing the generator is Ok. We have bypassed the regulator field control here and the generator will charge flat out if it is working OK. If there is still a low voltage reading of 6.25 volts then the generator is faulty. If the voltage is 8 volts plus then the voltage regulator is faulty and requires attention. Also very important that all battery power connections and earths a good throughout the car. Check battery terminals, starter solenoid terminals, ammeter terminals, etc. Should be tight, clean and not getting hot to the touch during operation. Regards, Kevin.

Kevin,

When you say " Join the Gen and Field wires together" Is it the Ground and Field wires? I don't have a terminal marked Gen.

JSeery · 07-24-2018, 06:35 PM

It is NOT ground! Read second Kavin post in #12, Gen or Arm.

solidaxle · 07-25-2018, 07:35 AM

Quote:

Originally Posted by JSeery

It is NOT ground! Read second Kavin post in #12, Gen or Arm.

I see where my confusion comes from. I went and searched for a 1939 wiring diagram. The Field/Generator connection for a "39", is different from my later set up with Armature/Field/Ground terminals.

koates · 07-25-2018, 10:53 PM

Armature (A) or Generator (Gen) are the same terminals but marked so on various generators and voltage regulators. Ground or Earth or "G"or Ë" are the chassis return to battery positive terminal on an old ford Positive ground system.

Ken/Alabama · 07-26-2018, 05:51 AM

Quote:

Originally Posted by fjz

Had my rebuilt generator and new voltage regulator tested and both are good. Did a voltage test and reading 6.94 at a fast idle. Amp gage reads -2. Suspect gage is bad. The replacement gages listed show a loop at the back whereas my original has 2 terminals. Has anyone been able to change the backs or should I connect my 2 wires run it through the loop? I also think my heat gage is bad as it reads hot when off. How do I check this gage?

The heat gauge reading hot when off is normal.

solidaxle · 07-26-2018, 12:15 PM

Quote:

Originally Posted by koates

Armature (A) or Generator (Gen) are the same terminals but marked so on various generators and voltage regulators. Ground or Earth or "G"or Ë" are the chassis return to battery positive terminal on an old ford Positive ground system.

Comprendo!

Thanks

Steve Seidl · 07-27-2018, 06:08 PM

You might want to check Harbor Freight if you have one in the area. They have a battery tester to test under load and also they have a charge check, They are in expensive, about $25.00. Works for me.

koates · 07-27-2018, 08:19 PM

Those elcheapo battery load testers only load a battery to around 100 amps maximum, which in most cases is no where high enough. Automotive 6 and 12 volt batteries need to be load tested to around 300 to 600 plus amps depending on the size or CCA capacity of the battery. A battery needs to be near fully charged before it is load tested. Good quality load testers are fairly expensive at around the 300.00 plus dollar range. One I bought quite a few years ago cost me $800.00. There are modern capacitance electronic battery testers around now which give a very good indication of the batteries plates internal condition. These are fairly expensive for a quality unit and most don't do 6 volt batteries. I have one that tests 6 volt batteries which I bought about 15 years ago when they were first on sale. Regards, Kevin.

rotorwrench · 07-28-2018, 12:19 PM

If a person has no recourse, they can attach the volt meter to the battery terminals and engage the starter. It will drop off some but should hold a steady voltage above 3.5 volts. If it drops much below 4-volts I'd be suspect. I tried that on a 12-volt battery that would consistently read 12.6-volts but when I hit the starter is dropped to 3-volts. I put in a new battery and it starts way better.

07-23-2018, 07:05 PM	#21
fjz Member Join Date: Jul 2017 Location: Belleville, Ontario Posts: 90	Re: 6 volt generator output After having my gens and vr's tested only to learn my original gen and rebuilt gen were both OK and my original vr is toast but the new one is OK I have come to the conclusion my amp meter is toast. Put my volt meter on the vr battery terminal and it read 6.94 with the engine on a fast idle. Been looking for an amp guage and the ones available do not have 2 terminals but rather a loop which I suspect the wire passes through. Has anyone switched backs on an amp guage?

07-23-2018, 07:53 PM	#22
JSeery Member Emeritus Join Date: Nov 2012 Location: Wichita KS Posts: 16,132	Re: 6 volt generator output The loop style is much "safer" because of the design. It is possible for the two terminal amp meters to malfunction resulting in a lot of heat and possible fire. Remember all of the amperage coming from the battery to the vehicle circuits passes through the ammeter on the terminal style. With the loop style the current is just passing by the meter (through the loop).

07-24-2018, 12:52 AM	#23
koates Senior Member Join Date: May 2010 Location: Melbourne Australia. Posts: 2,079	Re: 6 volt generator output So why do you think your ammeter is toast ?? Are the terminals burnt ? Also no good checking the generator voltage at a fast idle. You need the engine revs at 2000 RPM plus for around 3 minutes to test the generator output and voltage regulator setting which should be 7.3 to 7.5 volts. Do yourself a favour and get rid of that 10 year old battery and buy a new optima 6 volt battery. An old flat or faulty battery can effect the voltage reading at the regulator.

07-24-2018, 11:59 AM	#24
fjz Member Join Date: Jul 2017 Location: Belleville, Ontario Posts: 90	Re: 6 volt generator output Had my rebuilt generator and new voltage regulator tested and both are good. Did a voltage test and reading 6.94 at a fast idle. Amp gage reads -2. Suspect gage is bad. The replacement gages listed show a loop at the back whereas my original has 2 terminals. Has anyone been able to change the backs or should I connect my 2 wires run it through the loop? I also think my heat gage is bad as it reads hot when off. How do I check this gage?

07-24-2018, 12:13 PM	#25
fjz Member Join Date: Jul 2017 Location: Belleville, Ontario Posts: 90	Re: 6 volt generator output Koates my battery is also new. Reads 6.3 before I start. Reading 6.9 running tells me the gage is bad as it should not read -2 amps. Thanks Seery. Will order a new gage and connect my wires. How do I check the heat gage?

07-24-2018, 01:33 PM	#26
JSeery Member Emeritus Join Date: Nov 2012 Location: Wichita KS Posts: 16,132	Re: 6 volt generator output Sponsored Links (Register now to hide all advertisements) There have been a number of past threads on checking gauges. Basically use a 1 1/2 volt battery to see what the gauge reads, should be around mid gauge. On the -2 amps, have you tried switching the wires on the terminals?

07-24-2018, 02:15 PM	#27
fjz Member Join Date: Jul 2017 Location: Belleville, Ontario Posts: 90	Re: 6 volt generator output No but I will.

07-24-2018, 06:35 PM	#29
JSeery Member Emeritus Join Date: Nov 2012 Location: Wichita KS Posts: 16,132	Re: 6 volt generator output It is NOT ground! Read second Kavin post in #12, Gen or Arm.

07-25-2018, 10:53 PM	#31
koates Senior Member Join Date: May 2010 Location: Melbourne Australia. Posts: 2,079	Re: 6 volt generator output Armature (A) or Generator (Gen) are the same terminals but marked so on various generators and voltage regulators. Ground or Earth or "G"or Ë" are the chassis return to battery positive terminal on an old ford Positive ground system.

07-27-2018, 06:08 PM	#34
Steve Seidl Senior Member Join Date: May 2010 Location: Ham Lake,Minn Posts: 118	Re: 6 volt generator output You might want to check Harbor Freight if you have one in the area. They have a battery tester to test under load and also they have a charge check, They are in expensive, about $25.00. Works for me.

07-27-2018, 08:19 PM	#35
koates Senior Member Join Date: May 2010 Location: Melbourne Australia. Posts: 2,079	Re: 6 volt generator output Those elcheapo battery load testers only load a battery to around 100 amps maximum, which in most cases is no where high enough. Automotive 6 and 12 volt batteries need to be load tested to around 300 to 600 plus amps depending on the size or CCA capacity of the battery. A battery needs to be near fully charged before it is load tested. Good quality load testers are fairly expensive at around the 300.00 plus dollar range. One I bought quite a few years ago cost me $800.00. There are modern capacitance electronic battery testers around now which give a very good indication of the batteries plates internal condition. These are fairly expensive for a quality unit and most don't do 6 volt batteries. I have one that tests 6 volt batteries which I bought about 15 years ago when they were first on sale. Regards, Kevin.

07-28-2018, 12:19 PM	#36
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,426	Re: 6 volt generator output If a person has no recourse, they can attach the volt meter to the battery terminals and engage the starter. It will drop off some but should hold a steady voltage above 3.5 volts. If it drops much below 4-volts I'd be suspect. I tried that on a 12-volt battery that would consistently read 12.6-volts but when I hit the starter is dropped to 3-volts. I put in a new battery and it starts way better.